Aharonov-Bohm interferometer in inverted-band pn junctions

TL;DR

This paper proposes a new type of Aharonov-Bohm interferometer using inverted-band $pn$ junctions in 2D materials, demonstrating conductance oscillations and robustness to disorder, advancing electron optics in condensed matter.

Contribution

It introduces a novel AB interferometer design in inverted-band $pn$ junctions and analyzes the conditions for AB oscillations, including effects of graded interfaces and disorder.

Findings

AB oscillations observed in conductance simulations

Abrupt change in oscillation frequency at interface transition

Robustness of AB oscillations to disorder and temperature

Abstract

Inverted-band $pn$ junctions in two-dimensional materials offer a promising platform for electron optics in condensed matter, as they allow to manipulate and guide electron beams without the need for spatial confinement. In this work, we propose the realization of an Aharonov-Bohm (AB) interferometer using such $pn$ junctions. We observe AB oscillations in numerically obtained conductance and analytically identify the conditions for their appearance by analyzing the scattering processes at the $pn$ interface. To support experimental implementation, we also consider junctions with a graded interface, where the potential varies smoothly between the $p$- and $n$-doped regions. Our results reveal an abrupt change in the AB-oscillation frequency, which we attribute to a distinct transition in the hybridization across the interface. We verify that our reported AB oscillations are robust to realistic disorder and temperature decoherence channels. Our study paves the way for realizing the Aharonov-Bohm effect in bulk mesoscopic systems without the need for external spatial confinement, offering new possibilities in electron optics.